Predictive accuracy of intraocular lens power calculation using applanation ultrasound biometry: can we still rely on ultrasound biometry?

Abstract

Introduction: Ultrasound biometric measurements have long been the gold standard in cataract surgery. In the course of time, optical biometry replaced ultrasonography as the standard technique for axial length measurements of the eyes. However, optical biometry is not accessible in some centers; therefore, the present study was carried out to evaluate the predictability of refractive outcomes following phacoemulsification using applanation ultrasound biometry.

Methods: In this prospective study, ocular biometry was performed using an applanation ultrasound. Thereafter, mean absolute error (MAE) and the percentage of eyes achieving postoperative refraction within 0.5, 1.0, 1.5, and 2.0 D of the predicted spherical equivalent were calculated for SRK/T IOL formulas through a temporal clear corneal incision 1 month after phacoemulsification. Results: A number of 299 adult cataract patients (323 eyes in total) were enrolled. Absolute refractive mean error was obtained as 0.51±29 D 1 month after the surgery. In addition, 59.4% of the eyes achieved postoperative refraction of ±.5 D of the predicted value. Furthermore, 95.7 % of the eyes were found to be within ± 1.00 D. Conclusions: Based on the results of the present study, refractive outcomes after phacoemulsification using applanation ultrasound biometry are comparable with international standards for good practice and outcomes. It is worthy to note that this method offers considerable advantages, such as a few measurement limitations, cost-effectiveness, and accessibility.